The invention is particularly directed, but not limited, to the device of the above type which is used as an optional, auxiliary equipment for dispensing fertilizer and working in association with known and existing cultivator sweeps having a pointed nose portion and a pair of rearwardly divergent wings suitably shaped to work the soil as the sweep is forced through same. Some of such sweeps are known to be provided with seed distribution conduit system at the trailing end of the sweep for depositing the seeds to the soil at a suitable subsoil level.
The sweeps are usually secured to the frame of a farming implement by way of arcuately shaped shanks. The securement of the shanks, while virtually rigid, is usually accompanied by a resilient safety mechanism allowing retraction of the shank and thus of the sweep if the sweep encounters a solid obstacle such as a rock. This resilient mounting of the shank is well known and is not important for the function of the present invention. Therefore, for the purpose of the description of the invention, the shank is considered "rigid" with respect to the frame despite the fact that it always exhibits a degree of resiliency under severely overloaded conditions.
The subsoil application of seeds, fertilizer or other chemicals in granular, liquid or gaseous state or in a combination of same, and either separately or simultaneously, has been recognized as beneficial. A great variety of different devices for such application have been known and used.
U.S. Pat. NO. 3,618,538 (Brannan) shows a plow knife in which dry fertilizer is introduced at the back of the hoe. When viewed from the standpoint of the present invention, however, it fails to allow adjustability of the depth at which the fertilizer or the like is deposited. Nor is there means which would allow the dispensing or applicating device to be attached to an existing cultivator or the like unless complex and thus expensive modifications were made to same. U.S. Pat. No. 4,201,142 (Stump) and U.S. Pat. No. 4,628,839 (Edmisson) show other examples of the same basic approach to the problem.
U.S. Pat. No. 4,638,748 (Kopecky) discloses the combination of seed conduit with fertilizer release by a complex arrangement which presents an expensive solution. Moreover, it does not allow the flexibility of adjustable depth of deposition of the seeds, fertilizer or whatever material is being applied.
Canadian Patent 530,673 (Erdman) discloses an ejector type seeder machine. This patent shows that it is known to provide V-shaped sweeps with seed discharge means. From the standpoint of the present invention, however, it does not provide the possibility of administering another material, for instance a fertilizer, simultaneously with the deposition of the seeds and at a selectively adjustable level below the ground.
Canadian Patent 1,214,076 presents another interesting solution including a fertilizer feed tube 40 connecting to a fertilizer feed shank which, in turn, is secured to a rearwardly extending attachment boot. However, there is no inexpensive means of adding e.g. a fertilizer dispenser to an existing cultivator which is already provided with seed dispensing means.
U.S. Pat. No. 2,781,733 (Graham) shows a curved shank at the lower end of which is mounted a chisel the trailing surface of which coincides with a lower end of a shoe having passages for distributing a fertilizer. At the back of the hoe is provided inlet for fertilizer or the like in liquid form. The arrangement does not allow the use of the dispenser as an inexpensive, readily attachable auxiliary equipment. Nor do its structural features allow the selective adjustment of the subsoil depth at which the fertilizer is to be administered.